The purpose of this predoctoral and postdoctoral research training program is to provide rigorous training in the general fields of social, medical, and economic demography of aging. The program focuses on five substantive areas: a) biodemography, including indices and models of aging, vitality, and frailty, b) health disparities (by race/ethnicity, sex, socioeconomic status) among the elderly; c) international comparative studies of the health of aging populations in both developed and developing countries; d) important life course transitions (e.g., family changes, work and retirement, morbidity and disability) that relate to the health and well-being of aging persons; and e) the economics of aging. These areas require a core of researchers with doctoral and postdoctoral training who are skilled in state-of-the-art analytic methods and population modeling. The training program is administered through the Duke Population Research Institute (DuPRI), an interdisciplinary research organization of Duke University, and the Department of Sociology. Established in 2006, DuPRI constitutes a reorganization and expansion of population studies at Duke and replaces the Center for Demographic Studies, which was historically associated with this training grant. Predoctoral training is carried on with the full collaboration of the graduate training programs of the Departments of Sociology, Economics, and Public Policy in which doctorates are awarded. The training takes place at DuPRI, the Departments, and the Center for the Study of Aging and Human Development. The facilities at all these sites are utilized by both predoctoral and postdoctoral trainees. Eight predoctoral trainees with various background levels will be appointed in each year to conduct aging studies through the completion of their doctoral dissertations, normally four to five years for entering students with B.A. degrees. Trainees must fulfill all theory and methods requirements of a Ph.D. in sociology, economics, or public policy. In addition, all trainees must take required courses in the demography of aging and in demographic and statistical models and methods. At the postdoctoral level, two appointments of persons with a Ph.D. or equivalent degree will be made. These postdoctoral trainees typically will be recruited with varied levels of experience for two-year periods of training. They gain first-hand experience under direct supervision of preceptors on major ongoing research projects. They also are provided the opportunity of taking appropriate courses to obtain advanced training knowledge in needed methodological and substantive areas.